and carbonyl compounds 
both contain a 
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NCERT Exemplar Class 12 Chemistry Solutions chapter 12 Aldehydes, Ketones and Carboxylic Acids
Have you ever heard of Vanilin? It is the aldehyde, present in Vanilla that gives the Vanilla its characteristic smell. Just like this, aldehyde, ketones, and carboxylic acid are building blocks of several important organic compounds that are utilized in biological systems, industries, and drugs. Aldehydes and Ketones contain a carbonyl group and carboxylic acid contains a carboxyl group that gives them their reactivity and characteristic properties. This chapter includes their structure, preparation methods, properties, and their role in organic synthesis.
This Story also Contains
- NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: MCQ (Type 1)
- NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: MCQ (Type 2)
- NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: Short Answer Type
- NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: Matching Type
- NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: Assertion and Reason Type
- NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: Long Answer Type
- Class 12 Chemistry NCERT Chapter 12: Higher Order Thinking Skills (HOTS) Questions
- Approach to Solve Questions of Chapter 12 Aldehydes, Ketones, and Carboxylic Acids
- Major Subtopics OF NCERT Exemplar Class 12 Chemistry Solutions Chapter 12
- NCERT Exemplar Class 12 Chemistry Solutions
- NCERT Exemplar Class 12 Solutions
- NCERT Solutions for Class 12 Chemistry
- NCERT Solution subject-wise
- NCERT Notes subject-wise
To help students with the NCERT Exemplar of this chapter, our experts have carefully designed the solutions which have detailed explanations and a step-by-step problem-solving approach. The pattern of the solutions aligns with the CBSE board exams and also ensures students gain a deep understanding of reaction mechanisms, which helps students in competitive examinations.
Also Check, NCERT solutions for class 12
NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: MCQ (Type 1)
Question:1
Answer:
The answer is the option (ii) On addition of water to but-1-yne in the presence of H2SO4 and HgSO4 , 2-butanone is obtained (by Markovnikoff’s rule).
Question:2
Which of the following compounds is most reactive towards nucleophilic addition reactions?
Answer:
The answer is the option (i) CH3CHO (an aldehyde) is generally considered more reactive than ketones towards nucleophilic addition reactions. Ketones have 2 large substituents compared to 1 in aldehydes, that hinder the nucleophilic approach. Aldehydes are also considered more reactive because the 2 alkyl groups lead to the reduction of electrophilicity of the carbonyl carbon of ketone by releasing electron in its direction.
The reactivity order can be given as:
Question:3
The correct order of increasing acidic strength is _____________.
(i) Phenol < Ethanol < Chloroacetic acid < Acetic acid
(ii) Ethanol < Phenol < Chloroacetic acid < Acetic acid
(iii) Ethanol < Phenol < Acetic acid < Chloroacetic acid
(iv) Chloroacetic acid < Acetic acid < Phenol < Ethanol
Answer:
The answer is the option (iii) Due to formation of more stable conjugate base after removal of H+ phenol is more stable than the alcohol.
On the other hand, the stable conjugate base formed after removing H+ makes carboxylic acid more acidic than phenol.
In case chloroacetic acid, the presence of electron withdrawing chlorine group makes it more acidic compared to the acetic acid.
Question:4
Compound 
can be prepared by the reaction of _____________.
(i) Phenol and benzoic acid in the presence of NaOH
(ii) Phenol and benzoyl chloride in the presence of pyridine
(iii) Phenol and benzoyl chloride in the presence of ZnCl2
(iv) Phenol and benzaldehyde in the presence of palladium
Answer:
The answer is the option (ii) The compound C6H5OCOC6H5 can be prepared by the given below reaction. In this, the phenol is made to react with acid chloride in presence of an alkali. The alkali used is pyridine and acid chloride is benzoyl chloride.
Question:5
The reagent which does not react with both, acetone and benzaldehyde.
(i) Sodium hydrogen sulphite
(ii) Phenyl hydrazine
(iii) Fehling’s solution
(iv) Grignard reagent
Answer:
The answer is the option (iii) Fehling’s solution is the reagent that does not react with both acetone and benzaldehyde.
Question:6
Cannizaro’s reaction is not given by _____________.
Answer:
The answer is the option (iv)
CH3CHO contains 3 α-hydrogens while other three compounds have no any α -hydrogen. Hence, Cannizzaro’s reaction is given by them. Aldehydes without any alpha hydrogen undergo reduction and self-oxidation reaction when treated with conc. Alkali.
Question:7
Which product is formed when the compound
is treated with concentrated aqueous KOH solution?
Answer:
(ii) Benzaldehyde does not have any α hydrogen. When reacted with aqueous KOH solution, it gives Cannizzaro’s reaction.
Question:8
Structure of ‘A’ and type of isomerism in the above reaction are respectively.
(i) Prop-1-en-2-ol, metamerism
(ii) Prop-1-en-1-ol, tautomerism
(iii) Prop-2-en-2-ol, geometrical isomerism
(iv) Prop-1-en-2-ol, tautomerism
Answer:
The answer is the option (iv) A undergoes tautomerism to form acetone.
Question:9
Compounds A and C in the following reaction are __________.
(i) identical
(ii) positional isomers
(iii) functional isomers
(iv) optical isomers
Answer:
Thus, 
and CH3−CH2−CH2OH are positional isomers.
We know that acetaldehyde when treated with Grignard reagent followed by hydrolysis gives propane 2-ol.
Question:10
Which is the most suitable reagent for the following conversion?
(i) Tollen’s reagent
(ii) Benzoyl peroxide
(iii) I2 and NaOH solution
(iv) Sn and NaOH solution
Answer:
The answer is the option (iii) Iodoform test is most suitable for the given reaction.
Question:11
Which of the following compounds will give butanone on oxidation with alkaline KMnO4 solution?
(i) Butan-1-ol
(ii) Butan-2-ol
(iii) Both of these
(iv) None of these
Answer:
The answer is the option (ii). Aldehydes, when treated with common oxidising agents get readily oxidized to carboxylic acids.
Question:12
In Clemmensen Reduction carbonyl compound is treated with _____________.
(i) Zinc amalgam + HCl
(ii) Sodium amalgam + HCl
(iii) Zinc amalgam + nitric acid
(iv) Sodium amalgam + HNO3
Answer:
The answer is the option (i) Clemmensen reduction is used in the conversion of carbonyl group to CH2 group. In this reaction, zinc amalgam and HCl act as reagent.
NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: MCQ (Type 2)
Question:13
Which of the following compounds do not undergo aldol condensation ?
Answer:
The answer is the option (ii, iv)
Aldol condensation takes place only if α hydrogen is present. In the reaction, aldehydes and ketones with 1 or more than 1 alpha hydrogen react in presence of dilute alkali to form aldol and ketol respectively.
Question:14
Treatment of compound 
with NaOH solution yields
(i) Phenol
(ii) Sodium phenoxide
(iii) Sodium benzoate
(iv) Benzophenone
Answer:
The answer is the option (ii, iii) We get sodium phenoxide and sodium benzoate by nucleophilic substitution reaction.
Question:15
Which of the following conversions can be carried out by Clemmensen Reduction?
(i) Benzaldehyde into benzyl alcohol
(ii) Cyclohexanone into cyclohexane
(iii) Benzoyl chloride into benzaldehyde
(iv) Benzophenone into diphenyl methane
Answer:
The answer is the option (ii, iv)
Clemmensen reduction is used in the conversion of carbonyl group of aldehydes and ketones to CH2 group when treated with zinc amalgam and conc. HCl. It is used to convert cyclohexanone into cyclohexane and benzophenone into diphenyl methane.
Question:16
Through which of the following reactions number of carbon atoms can be increased in the chain?
(i) Grignard reaction
(ii) Cannizaro’s reaction
(iii) Aldol condensation
(iv) HVZ reaction
Answer:
The answer is the option (i,iii) Grignard reaction is used to increase the number of carbon atom in chain. Aldol condensation increases the number of carbon atom in the chain for aldehydes and ketones.
Question:17
Benzophenone can be obtained by ____________.
(i) Benzoyl chloride + Benzene + AlCl3
(ii) Benzoyl chloride + Diphenyl cadmium
(iii) Benzoyl chloride + Phenyl magnesium chloride
(iv) Benzene + Carbon monoxide + ZnCl2
Answer:
The answer is the option (i,ii) Benzophenone can be obtained by either of benzoyl chloride + diphenylcadmium or benzoyl chloride+ benzene+ AlCI3 . The latter is referred to as Friedel-Craft acylation reaction.
Question:18
The answer is the option (i,ii) The 2 possible orientation of a planar molecule of carbonyl compound in case of nucleophilic attack are:
The nucleophililic attack can occur either from front or rear side.
NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: Short Answer Type
Question:19
Why is there a large difference in the boiling points of butanal and butan-1 -ol ?
Answer:
There is a huge difference in the boiling points of butanal and butan-1 -ol due to the presence of intermolecular hydrogen bonding between -OH groups in alcohol.
Question:20
Write a test to differentiate between pentan-2-one and pentan-3-one.
Answer:
The answer is Idoform test. There is a CH3CO group in Pentan-2-one and that is why it will give a positive iodoform test.
Question:21
Give the IUPAC names of the following compounds
Answer:
(i) 3-Phenylprop-2-en-1 -al
(ii) Cyclohexanecarbaldehyde
(iii) 3-Oxopentan-l-al
(iv) But-2-en-l-al
Question:23
Write IUPAC names of the following structures.
Answer:
(i) Ethane-1,2-dial
(ii) Benzene-1, 4-dicarbaldehyde
(iii) 3-Bromobenzaldehyde
Question:24
Reactions for obtaining benzalchloride and benzaldehyde from it are:
Question:25
The electrophile produced in the reaction of benzene with benzoyl chloride in the presence of anhydrous AlCl3 is benzoylium cation. The product formed in this reaction is benzophenone. This reaction is called Friedel Craft's acylation reaction.
Question:26
The products formed on oxidation of 2, 5-dimethylhexan-3-one are: -
2-Methylpropanoic acid
Ethanoic acid and
Methanoic acid.
3-Methylbutanoic acid
Question:27
FCH2COOH>ClCH2COOH>C6H5CH2COOH>CH3COOH>CH3CH2OH
The electron-withdrawing group increase the acidity of carboxylic acids since they stabilize the conjugate base by delocalization of charge. Whereas the electron donating group decrease the acidity as the resulting conjugate base is unstable.
Higher the electronegativity, greater the acidic strength.
(i.e,F>Cl>C6H5>H)
Question:28
On reaction of propanal with 2-methyl propanal in the presence of NaOH, aldehyde mixture is formed.
Question:29
It is given that B and A on heating together in the presence of acid produces a fruity smelling compound which is ester.
-
Carboxylic Acid
-
Alcohol
-
Ester Group
Question:30
NO2CH2COOH>FCH2COOH>C6H5COOH
-NO2 and -F groups are electron withdrawing groups that increase the acidity due to stable nature of resulting conjugate base. Whereas the electron-donating group decrease the acidity as the resulting conjugate base is unstable.
Higher the electronegativity, greater the acidic strength.
Question:31
In carbonyl groups, carbon acquires a partial positive charge because oxygen is more electronegative. Thus, carbonyl group is polar in nature and hence susceptible to nucleophilic addition reaction. Alkenes, on the other hand are non-polar and electron abundant; making them susceptible to electrophilic addition reaction.
Question:32
Carboxylic acid doesnt show nucleophilic substitution reaction as because of presence of lone pair atoms on O atom of OH group decreases electrophilic character of carbonyl carbon by resonance.. Hence partial positive charge decreases and therefore it doesnt show nucleophilic substitution reactions
Question:33
Identify the compounds A, B and C in the following reaction.
Answer:
-
Compound A is CH3−MgBr
-
Compound B is CH3−COOH
-
Compound C is CH3−COOCH3
Question:34
Acidity depends upon the stability of the resulting conjugate base. In case of carboxylic acid, equivalent resonance structures stabilize the carboxylate ion as the negative charge is at the more electronegative oxygen atom. Phenoxide ion, conjugate base of phenol does not have equivalent resonance structure as the negative charge is on the less electronegative carbon atom.
Question:36
Answer:
The reason is formation of polysubstituted products. Friedel-craft’s acylation reaction can be used to avoid the formation of these products.
Question:37
Can Gatterman-Koch reaction be considered similar to Friedel Craft’s acylation? Discuss.
Answer:
Yes, the Gattermann-Koch reaction can be considered similar to Friedel Craft’s acylation reaction. In Gattermann-Koch reaction introduction of -CHO group to the benzene nucleus takes place by reacting CO with HCl gas. In Friedel-Crafts acylation reactions, treatment of benzene or any arene with an acid chloride in presence of anhydrous AlCl3 takes place. In this RCO group is introduced.
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NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: Matching Type
Question:38
Match the common names given in Column I with the IUPAC names given in Column II
|
Column I (Common names) |
Column II (IUPAC names) |
|
(i) Cinnamaldehyde |
(a) Pentanal |
|
(ii) Acetophenone |
(b) Prop-2-enal |
|
(iii) Valeraldehyde |
(c) 4-Methylpent -3-en-2-one |
|
(iv) Acrolein |
(d) 3-phenylprop-2-enal |
|
(v) Mesityl oxide |
(e) 1-Phenylethanone |
Answer:
(i → d), (ii → e), (iii → a), (iv → b), (v → c)
Question:39
Match the acids given in Column I with their correct IUPAC names given in Column II.
|
Column I (Acids) |
Column II(IUPAC names) |
|
(i) Phthalic acid |
(a) Hexane-1,6-dioic acid |
|
(ii) Oxalic acid |
(b) Benzene-1, 2-dicarboxylic acid |
|
(iii) Succinic acid |
(c) Pentane -1 , 5-dioic acid |
|
(iv) Adipic acid |
(d) Butane -1, 4-dioic acid |
|
(v) Glutaric acid |
(e) Ethane-1,2-dioic acid |
Answer:
(i → b), (ii → e), (iii → d), (iv → a), (v → c)
Question:40
Match the reactions given in Column I with the suitable reagents given in Column II.
|
Column I (Reactions) |
Column II (Reagents) |
|
(i) Benzophenone → Diphenylmethane |
(a) LiAIH4 |
|
(ii) Benzaldehyde → 1-Phenylethanol |
(b) DIBAL-H |
|
(iii) Cyclohexanone → Cyclohexanol |
(c) Zn (Hg)/Conc.HCl |
|
(iv) Phenyl benzoate → Benzaldehyde |
(d) CH3MgBr |
Answer:
(i → c), (ii → d), (iii → a), (iv → b)
Question:41
Match the example given in Column I with the name of the reaction in Column II
|
Column I (Examples) |
Column II (Reaction) | ||
|
(i) |
|
(a) |
Friedel-Crafts acylation |
|
(ii) |
|
(b) |
HVZ reaction |
|
(iii) |
|
(c) |
Aldol condensation |
|
(iv) |
|
(d) |
Cannizzaro's reaction |
|
(v) |
|
(e) |
Rosenmund's reduction |
|
(vi) |
|
(f) |
Stephen's reaction |
Answer:
(i → e), (ii → d), (iii → a), (iv →b), (v → f), (vi → c)
NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: Assertion and Reason Type
Question:42
In the following question a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Formaldehyde is a planar molecule.
Reason: It contains sp2 hybridised carbon atom.
(i) Assertion and reason both are correct and the reason is the correct explanation of assertion.
(ii) Assertion and reason both are wrong statements.
(iii) The assertion is a correct statement but the reason is the wrong statement.
(iv) The assertion is a wrong statement but the reason is the correct statement.
(v) Assertion and reason both are correct statements but the reason is not the correct
explanation of assertion.
Answer:
The answer is the option (i). Formaldehyde contains sp2 hybridized carbon atom. That is why it is a planar molecule. Both the assertion and reason are correct, and reason is correct explanation of assertion.
Question:43
In the following question a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Compounds containing -CHO group are easily oxidised to corresponding carboxylic acids.
Reason: Carboxylic acids can be reduced to alcohols by treatment with LiAlH4
(i) Assertion and reason both are correct and the reason is the correct explanation of assertion.
(ii) Assertion and reason both are wrong statements.
(iii) The assertion is a correct statement but the reason is the wrong statement.
(iv) The assertion is a wrong statement but the reason is the correct statement.
(v) Assertion and reason both are correct statements but the reason is not the correct
explanation of assertion
Answer:
The answer is the option (v). Due to high electronegativity of oxygen, carbonyl group in aldehydes are a strong electron-withdrawing group. This weakens the C−H bond in aldehydes. Even a weak oxidizing agent can oxidize the aldehydes into the corresponding carboxylic acids.
Question:44
In the following question a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: The α-hydrogen atom in carbonyl compounds is less acidic.
Reason: The anion formed after the loss of the α-hydrogen atom is resonance stabilised.
(i) Assertion and reason both are correct and the reason is the correct explanation of assertion.
(ii) Assertion and reason both are wrong statements.
(iii) The assertion is a correct statement but the reason is the wrong statement.
(iv) The assertion is a wrong statement but the reason is the correct statement.
(v) Assertion and reason both are correct statements but the reason is not the correct
explanation of assertion
Answer:
The answer is the option (iv). The α -hydrogen atom in carbonyl compounds is more acidic. Carboxylic acids on dissociation in water give resonance stabilized carboxylate anions and hydronium ion.
Question:45
In the following question a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Aromatic aldehydes and formaldehyde undergo Cannizaro reaction.
Reason: Aromatic aldehydes are almost as reactive as formaldehyde.
(i) Assertion and reason both are correct and the reason is the correct explanation of assertion.
(ii) Assertion and reason both are wrong statements.
(iii) The assertion is a correct statement but the reason is the wrong statement.
(iv) The assertion is a wrong statement but the reason is the correct statement.
(v) Assertion and reason both are correct statements but the reason is not the correct
explanation of assertion.
Answer:
The answer is the option (iii). Aromatic aldehydes and formaldehyde do not have a-hydrogen and thus undergo Cannizzaro’s reaction. Aldehydes with no alpha hydrogen atom undergo oxidation and reduction reaction when treated with conc. Alkali.
Question:46
In the following question a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Aldehydes and ketones, both react with Tollen’s reagent to form a silver mirror.
Reason: Both, aldehydes and ketones contain a carbonyl group.
(i) Assertion and reason both are correct and the reason is the correct explanation of assertion.
(ii) Assertion and reason both are wrong statements.
(iii) The assertion is a correct statement but the reason is the wrong statement.
(iv) The assertion is a wrong statement but the reason is the correct statement.
(v) Assertion and reason both are correct statements but the reason is not the correct
explanation of assertion.
Answer:
The answer is the option (iv) Aldehyde and ketones both have carbonyl group but only the former undergoes reaction with Tollen’s reagent to give silver mirror.
NCERT Exemplar Class 12 Chemistry Solutions Chapter 12: Long Answer Type
Question:47
As compound B turns up with a positive result for Fehling’s test, it is an aldehyde. It also gives a positive result to the iodoform test, which implies that it has a -COCH3 group. Compound C with a positive iodoform test and negative Fehling’s test, is a ketone.
Question:48
Answer:
Molecular formula of the compound in question is C8H8O. It is given that ‘A’ does not give Tollens’ or Fehling’s test, making it a ketone. Since we get positive test with 2, 4-DNP and iodoform test, It means it is methyl ketone.
Question:49
C3H6O will have following isomer.
Compound 1 (Propanal) is more susceptible to a reaction with HCN as carbon atom in carbonyl group acquires more positive charge than carbon atom in compound 2 (propan-2-one). Moreover, there is much less static hindrance in compound 1 compared to compound 2.
Equilibrium is established in this reaction as it is reversible in nature. Addition of an acid hinders the formation of CN− ion and thus, can stop the reaction.
Question:50
Since liquid A forms a bright silver mirror when treated with ammoniacal AgNO3 solution it is an aldehyde.
In the same way, liquid ‘B’ must be a methyl ketone for it does not give test with ammoniacal AgNO3 solution.
Chemical equations for these reactions are :
Studying the chapter “Aldehydes, Ketones and Carboxylic Acids” from Class 12 Chemistry NCERT exemplar solutions chapter 12 will not only help you to write IUPAC names of different ketones, aldehydes, and carboxylic acids, but will also help you to remember these for future.
Class 12 Chemistry NCERT Chapter 12: Higher Order Thinking Skills (HOTS) Questions
Question 1: An organic compound $(\mathrm{X})$ with molecular formula $\mathrm{C}_3 \mathrm{H}_6 \mathrm{O}$ is not readily oxidised. On reduction it gives $\left(\mathrm{C}_3 \mathrm{H}_8 \mathrm{O}(\mathrm{Y})\right.$ which reacts with HBr to give a bromide ( Z ) which is converted to Grignard reagent. This Grinard reagent on reaction with (X) followed by hydrolysis give 2,3-dimethylbutan-2-ol. Compounds $(\mathrm{X}),(\mathrm{Y})$ and $(\mathrm{Z})$ respectively are :
1) $\mathrm{CH}_3 \mathrm{COCH}_3, \mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{OH}, \mathrm{CH}_3 \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_3$
2) $\mathrm{CH}_3 \mathrm{COCH}_3, \mathrm{CH}_3 \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_3, \mathrm{CH}_3 \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_3$
3) $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CHO}, \mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{OH}, \mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{Br}$
4) $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CHO}, \mathrm{CH}_3 \mathrm{CH}=\mathrm{CH}_2, \mathrm{CH}_3 \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_3$
Answer:
Hence, the correct answer is option (2).
Question 2:
Match List -I with List -II
| List-I | List-II |
 | (I) Etard reaction |
 | (II) Gatterman -Koch reaction |
 | (III) Rosenmund reduction |
 | (IV) Stephen reaction |
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Download EBookChoose the correct answer from the options given below :
1) (A)-(IV), (B)-(III), (C)-(I), (D)-(II)
2) (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
3) (A)-(I), (B)-(III), (C)-(II), (D)-(IV)
4) (A)-(III), (B)-(IV), (C)-(I), (D)-(II)
Answer:
List-I
(A) $\mathrm{RCN} \xrightarrow[\text { (ii) } \mathrm{H}_3 \mathrm{O}^{+}]{\text {(i) } \mathrm{SnCl}_2, \mathrm{HCl}} \mathrm{RCHO}$
Stephen reaction
(B) 
Rosenmund reduction
Etard reaction
Gatterman -Koch reaction
Hence, the correct answer is option (1).
Approach to Solve Questions of Chapter 12 Aldehydes, Ketones, and Carboxylic Acids
It is recommended to strategize your study plan and question approach to solve the questions of this chapter. The following are the points that will help you build a good approach.
1. Understand functional groups & nomenclature
It is easy yet crucial as there will be reactions on specific functional groups. To solve the question you also need to draw the structures of the given compound.
2. Grasp the general preparation methods
Know how each class is prepared from alcohols (oxidation), nitriles/hydrolysis, acid chlorides, Grignard reagents, etc. Also learn to write balanced reactions with reagents and conditions.
3. Master Important reactions and mechanisms
For Aldehydes and Ketones-
- Nucleophilic addition reactions (e.g., HCN, NaHSO₃, Grignard reagents).
- Reduction and oxidation reactions.
- Aldol condensation, Cannizzaro reaction.
For Carboxylic Acids-
- Acid-base reactions, decarboxylation, esterification (Fischer esterification).
- Substitution on –COOH group, like Hell–Volhard–Zelinsky reaction.
4. Learn oxidation and reduction trends
Learn the specifity of the reagents used and their reactivity order.
- Oxidizing agents- KMnO₄, H₂CrO₄, Tollen’s, Fehling’s.
- Reducing agents- LiAlH₄, NaBH₄, Zn-HCl (Clemmensen), NH₂NH₂-KOH (Wolff–Kishner).
5. Pay attention to Named Reactions
These are too important as most of the time they are asked directly in the exams.
- Aldol Condensation
- Cannizzaro Reaction
- Rosenmund Reduction
- Stephen Reduction
- Hell–Volhard–Zelinsky Reaction
7. Practice conversion & interconversion problems
Practice all sort of problems. You can refer to NCERT intext questions and solved examples. Also, try to solve the NCERT Exemplar and previous years questions.
Major Subtopics OF NCERT Exemplar Class 12 Chemistry Solutions Chapter 12
- Nomenclature and Structure of Carbonyl Group
- Preparation Of Aldehydes And Ketones
- Physical Properties of Aldehydes and Ketones
- Chemical Reactions of Aldehydes and Ketones
- Uses of Aldehydes and Ketones
- Structure of Carboxyl Group
- Nomenclature of Carboxyl Group
- Methods of Preparation of Carboxylic Acids
- Physical Properties of Carboxylic Acids
- Chemical Reactions of Carboxylic Acids
- Uses of Carboxylic Acids
NCERT Exemplar Class 12 Chemistry Solutions
NCERT Exemplar Class 12 Solutions
NCERT Solutions for Class 12 Chemistry
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Frequently Asked Questions (FAQs)
Q: How to distinguish between an aldehyde and a ketone using a simple test?
A:
A common test to distinguish between aldehydes and ketones is the Tollens' test. Aldehydes can reduce Tollens' reagent to form a silver mirror, indicating the presence of an aldehyde. Ketones, however, do not react with Tollens' reagent and thus will not produce a silver mirror.
Q: What are some common methods for synthesizing aldehydes and ketones?
A:
Aldehydes and ketones can be synthesized using several methods. Aldehydes are commonly prepared by the oxidation of primary alcohols, while ketones can be formed by the oxidation of secondary alcohols. Another method is the Friedel-Crafts acylation, where an acyl group is added to an aromatic ring using an acid chloride in the presence of a Lewis acid catalyst.
Q: What is the significance of the carbonyl group in aldehydes and ketones?
A:
The carbonyl group is significant in aldehydes and ketones because it is a polar functional group that greatly affects the physical and chemical properties of these compounds. This polar nature allows them to form hydrogen bonds with water, making aldehydes and many ketones soluble in water.
Q: How can carboxylic acids be converted into derivatives such as esters and amides?
A:
Carboxylic acids can be converted into derivatives by reacting them with alcohols to form esters, a process known as esterification. This reaction typically requires an acid catalyst and can be reversible. Similarly, carboxylic acids can be converted into amides by reacting them with ammonia or amines.
Q: What will the students learn from NCERT Exemplar Class 12 Chemistry solutions chapter 12?
A:
Students will learn about physical properties, uses and chemical reactions of very crucial hydrocarbons like Aldehydes, Ketones, and Carboxylic Acids alongside it’s nomenclatures and various structures of the carboxyl groups and the IUPAC names of different ketones, aldehydes, and carboxylic acids.
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Yes, if you’re not satisfied with your marks even after the improvement exam, many education boards allow you to reappear as a private candidate next year to improve your scores. This means you can register independently, study at your own pace, and take the exams without attending regular classes. It’s a good option to improve your results and open up more opportunities for higher studies or careers. Just make sure to check the specific rules and deadlines of your education board so you don’t miss the registration window. Keep your focus, and you will do better next time.
Hello Aspirant,
Yes, in the case that you appeared for the 2025 improvement exam and your roll number is different from what was on the previous year’s marksheet, the board will usually release a new migration certificate. This is because the migration certificate will reflect the most recent exam details, roll number and passing year. You can apply to get it from your board using the process prescribed by them either online or through your school/college.
Yes, if you miss the 1st CBSE exam due to valid reasons, then you can appear for the 2nd CBSE compartment exam.
From the academic year 2026, the board will conduct the CBSE 10th exam twice a year, while the CBSE 12th exam will be held once, as per usual. For class 10th, the second phase exam will act as the supplementary exam. Check out information on w hen the CBSE first exam 2026 will be conducted and changes in 2026 CBSE Board exam by clicking on the link .
If you want to change your stream to humanities after getting a compartment in one subject in the CBSE 12th Board Exam , you actually have limited options to qualify for your board exams. You can prepare effectively and appear in the compartment examination for mathematics again. If you do not wish to continue with the current stream, you can take readmission in the Humanities stream and start from Class 11th again, and continue studying for two more years to qualify for the 12th examination.
The GUJCET Merit List is prepared based on the Class 12th marks and GUJCET marks received by the students. CBSE students who are not from the Gujarat board can definitely compete with GSEB students, as their eligibility is decided based on the combined marks scored by them in GUJCET and the 12th board. The weightage of the GUJCET score is 40% and the weightage of the class 12 scores is 60%.
Popular CBSE Class 12th Questions
A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is
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An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range
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A particle is projected at 600 to the horizontal with a kinetic energy . The kinetic energy at the highest point
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In the reaction,
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How many moles of magnesium phosphate, will contain 0.25 mole of oxygen atoms?
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0.02 |
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3.125 × 10-2 |
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1.25 × 10-2 |
Option 4)
2.5 × 10-2 |
Colleges After 12th
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